Portable devices such as tablets, phone and Ultrabook devices that are available in the market support the use of a stylus or a stylus device. For example, among other types of stylus supported is an active stylus, which carries its own power source to power itself. This feature is particularly attractive due to supporting finer stylus tips enabling more natural writing experience, better noise immunity and its ability to add extra functions such as eraser and pressure sensitivity in the stylus.
One problem with the active stylus has been the need to incorporate a battery to accommodate the power needs of the circuitry. The incorporation of the battery (e.g., AA batteries) increases the thickness and weight of the stylus, and affects the balance on the stylus. This is in addition to the need to replace batteries on the stylus periodically.
Thus, an ideal active stylus solution may have the following features: long battery life, which is typically measured in several months with 8 hour usage per day; a light weight and proper distribution of weight to mimic a traditional pen; and an ability to be quickly charged in the event of a discharge without relying on components that are external to the computer system. As such, there is a need for a design to provide the solution as described above.